Stuffing box



G. F. WILSON Oct. 27, 1931.

STUFFING 1301(- Filed Oct. 5, 1928 Patented Oct. 27, 1931- UNITED STATES PATENT OFFICE GEORGE F. WILSON, OF AKRON, OHIO, ASSIGN'OR TO THE B. F. GOODRICH COMPANY, OF NEW YORK, N. Y., CORPORATION OF NEW YORK STUFFING- BOX Application filed October 5, 1928." Serial No. 310,606;

This invention relates to stuffing boxes, and especially to stufling boxes used on the shafts of machines for grinding abrasive material or the like in which situation it is important that none of the material being ground passes thesuffing box and gets into the bearings of the'shaft.

The chief objects of the invention are to prevent solid material from passing between the stuffing box and the shaft; to prevent scoring of the shaft by said material; automatically to remove any solid material which may pass through'the stufiing box; and to cool the shaft and stufiing box.

' The forgoing objects are accomplished by means of a stufling box employing fluid pressure of such magnitude as to create a diflerential of fluid pressure. on opposite sides of the stufiing box, which pressure is greatest on the opposite sideof the box from the material being ground. The result is that in case of wear in the packing of the stufling box, fluid will flow from the latter instead of into'it and the entrance of solid matter is prevented; The fluid in the stuffing box preferably is maintained in circulation so that it serves as a cooling medium, and it also serves to carry away any solid material which may work its way through'the box against the fluid'pressure during an interval of abnormal pressure in the grinding cham- -ber. I

Of the accompanying drawings Fig. 1 is a vertical longitudinal section through grinding apparatus embodying my invention in its preferred form, a part being in elevation.

Fig. 2 is a sectional detail, on a larger scale, of the stuffing box therein.

Fig. 3 is a detail side elevation of an element of the stuffing box. Referring to the drawings, 10 is a base casting, 11 the housing, and 12 the cover of a grinding or comminuting machine of known construction adapted especially for wet grinding the housing being formed, behind the cover 12, with a grinding chamber 13 in which is mounted the stator member 14 of the grinding mechanism. The stator 14 comprises an annular, rearwardly-tapered structered with the passages 32, 33.

ture having its inner periphery roughened or corrugated, and is spaced from the surroundlnghousing structure to provide a water acket 15 of which 16 is the inlet pipe and 17 the outlet pipe thereof. A driven horizontal shaft 18 is journaled in the housing 11 in a sleeve bearing 19 and in other bearings (not shown), and the housing is formed with chambers 20, 21, and 22 for containing the lubricating oil for said bearings. Mounted upon the end of the shaft 18 in the grinding chamber 13 and concentric with the stator 14 :is a'frusto-conical grinding rotor 24 which has a roughened or corrugated periphery adapted to cooperate with the corrugated sur- 14, and an outlet passage 27 formed in the housing 11 and communicating with the rear 'of the chamber 13 and with apipe 28 is provided for carrying off the comminuted material. A through passage 29 extending transversely of the housing 11 is formed therein between the chambers 13 and 22, and my improved stufiing box, designated 30, is mounted in an aperture 31 in the housing wall between the chamber 13 and passage 29, surrounding the shaft 18. Passages 32, 33 extending through the wall of the housing 11 intersect the aperture 31 at top and bottom near the middle thereof but in different vertical planes, the outer ends of said passages communicating respectively with a fluid supply pipe 34 and a drain pipe 35. As shown in Fig. 1, the passage 32 and pipe 34 are of greater capacity than the passage 33 and pipe 35.

The stuffing box 30 comprises an annular bushing 36 mounted in the aperture 31 and having one of its ends formed exteriorly with a circumferential flange 37 seated in a complemental counterbore in the aperture 31 and having its opposite end extending into the passage 29 and formed interiorly with a screw thread 38. The bushing 36 is formed with centrally-positioned apertures 39, 40 regis- The flanged end of the bushing 36 is closed by an annular cap 41 which telescopes with the end portion of the bushing and is secured in place by screws such as thescrew 42, or by any other suitable means. The end face 'of the cap 41 which lies within the bushing 36.

.is sloped outwardly. in the direction toward its inner periphery.

H The other end of thebushing 36; is by agland43 which is-threaded into the'screw thread 38. The outer end of the gland 43' is formed exteriorly with a circumferential fiange44 of somewhat smaller diameter than the aperture 31, and said flange is formed with a plurality of spaced-apart notches, such as the'notch 45,-by-which the gland: may be engaged by a spanner wrench, insertedJin the 'passage 29, "for tighteningor loosening; it.

Theend'. face ofthe gland 43Iwhich lies with; i in the bushing 36 is'sloped outwardlyin the directiontoward' its innerperiphery-J V Mounted bushin'ghfibetween the cap and gland 43a-re a.-.pair='of:.annular, spaced apart packing members 46, 46,.whichim crosssection are \irsha'ped, being tapered toward their outer peripheries. Positioned; between -the' packing members is an.annular,.complementally-shaped,' metal spacer-ring 47 the outer periphery of which-snugly fits Within the'bushing 36, its innerperiphery being spaced from the shaft 18 to=provide a passageway for fluidtherebetween. The arrangementis' suchithat-I when; the gland 435 is set upagainst the adjacent packing member 46, bothpacking meinbers' willzbeconipressed "and urged radiallyinwardi against the shaft 1 The spacer ring 47 is formed: in its, outer periphery with a pair ofparallel circumfer- -ential grooves 48, 49. which. intersect therespective apertures- 39,40. of the: bushing 86 whenthespacer ring ismountedrthereinzr A plurality of radial-passages 50. are formed in the ring 47 extending from the circumferential groove48 to the inner periphery. of the wring parallel tothe adjacent side ofthe lat- .ter'; and similar 'seriesof passages 51, 5 1

'extendafrointhe groove 49 to the inner periphery of the ring, the=passages 50and 51 being =.positijoned I in alternation circumferentially of. the ring-.-

The. stniiing box functions in the following nianner. 71th the various parts. assembled as shown anddescribed andthe shaft 1 8-be- .i

ng driven to drive the rotor 24: and there n to com mmnte, the sohdmatter 111 a wet n11 fed into the grinding chamber l3- thr ough inletpipe 25,' water under pressure is ad- 'initted through the pipe 34 andp'ztsses through the passage 32, aperture 39, groove 49 and p'assagesl into the space between the shaft 18 and spacer-ring-4'Z. The water-flows 'ontfrom said space through th'e passages 50, groove 48, aperture 40, passage 33iand drain pipe 35. The alternate positioningofathe tion of: paek ngikmenibiers in. the; shi ting hex. tor

passages 56, 51 induces a circulation of the water in the space between the spacer-ring 47 and shaft 18 circumferentiallv of the latter. i

The passage 33 being smaller than the pas-' sage32; the flow of wateris retarded thereat andlexcess pressure is built up inthe stufiing boX.. Said pressure is maintained somewhat higher than the normal pressure of the wet I Di X in the grindi'ng chaniber 1-3 with the result that when "the packing 46 becomes so worn ias normally to permit leakage of the mix along theshaft into the stufiing box, such The in-Ventionrinay bevariously: modified within.- the: scope. on the appended? claims.

Izclaims- ;-1 1 I v 1.. In a stuifingbox a'ssernblythe combination of a shaft,.a stufiingiboxgtherefor, a pair of packing. members. in. the st-ufling "box." for confining fluid on oneside thereof, a; spacerning positioned: between; said; packing members Y and .standingaclear of; the shaft so as to define. a' passage fo r'fluid" thereabout, and

means for conducting flnid to-andfrom the spacer-ring, saidspacerring being provided with: means adapted; to: preventthe flow of fluid from; the inlet to the outlet except. by way. ot the. passage,..toi efiect, circulation of f the fl uidiwithinthe passage and being formed on.v its outer;v periphery with a. pair; of" ci cumferentialngrooyes in commnnicatlon with thefinid? and inlet respectively; and. having a...pl,u,nal,ityof radiallyfdirected fluid passages-extending from said. grooye tot e inner periphery offthe ring-,the finiclrpas'sag' from the respectivegrooves being disposed in alternationjcircninferentially f-the; ring.

2;;In stufiing box assembly the combination; 'o'f sha t, a :stnfli g; box: th i a pair. o p cking. member int u i g box for .confi'nin fluid on one side thereof,fa spacer-ring. rav ng. plurality of fluid-conductingchannelsuand being positioned be tween; a d-.pac. .ns= memb an ta dm clear of said shaft s aste-define a'passage f rsfluld her bputa a d: me -a t r condu i u dr ta nd-firm sai P s g a spacerring beingprovidedwith flow-restrict- :ing lands between. itschannels for; effecting; po it e C rculation of fl a hwi ah, said ipassageinecontactiwith'th'eshaft..

3.='.- ;n. astufiing. .bc faassem lyhe e mbir "l a shaft, a sti ng cxtherefor; p ir confining fluid on one side thereof, a structure including a spacer ring positioned between said pacln'ng members and defining with said shaft a passage for fluid thereabout, said structure being formed with inlet and outlet channels communicating with said passage, at least one of said channels being circumferentially disposed with respect to the shaft, and means to prevent the flow of fluid from the inlet to the outlet channels except by way of said passage.

In Witness whereof I have hereunto set my hand this 27th day of Se tember, 1928.

GEORG F. WILSON. 

